Control for lighting effects



May 27, 1947. I L. P. CLARK 2,421,116

CONTROL FOR LIGHTING EFFECTS Filed April 2, 1942 INVENTOR LEW/.5 CLARK ATTORNEYS Patented May 27, 1947 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to control apparatus ior lighting effects, and more especially it relates to means for producing a pulsation or flutter in the light given oil by electric, metallic filament lamps in simulation of the flicker of candle light or the pulsation of neon lamps.

More specifically the invention resides in an improved switch structure that is adapted to be used in the electrical circuit comprising the lamps to be flickered. In its broadest aspects the switch is a pneumatically operated device.

The chief objects of the invention are to provide in an improved manner for the construction of pneumatically operated electrical switches of the character mentioned; to provide a phone matically operated switch structure wherein the air current is thermally induced; and to provide a switch structure that will effect an intermittent making and breaking of the electrical circuit notwithstanding the constant flow of the pneumatic medium. Other objects will be manifest as the description proceeds.

The single figure of the accompanying drawing is an electrical circuit for lighting efiects showing the improved switch, partly in section, operatively interposed therein.

Referring to the figure of drawing, there is shown a main circuit comprising a resistance element and a bank of lamps, the lamps being dimmed by reason of said resistance element, a shunt circuit around said resistance element, and means automatically and intermittently opening and closing said shunt circuit to the end that full unresisted current may be delivered to the bank of lamps intermittently to brighten the same.

More specifically there is shown a main circuit consisting of a pair of terminals ID by which the circuit is adapted to be connected for excitation with any suitable alternating current source, a conductor H connecting one of said terminals with one side of a bank of lamps l2, a conductor l3 connecting the other terminal H] with the coils of a variable resistance unit l4, and a conductor [5 connecting the movable arm of the resistance unit 14 to the other side of the bank of lamps [2. The latter are shown as being connected in parallel, but they will operate equally as well when connected in series. Although the resistance unit 14 is shown as a rheostat, it is not necessarily so and may be of fixed resistance if desired.

The improved switch of the invention is located in a shunt circuit in the wiring diagram, as presently will be explained, said switch comprising a pair of rings or loops 42, 43 that are arranged in spaced apart axial alignment, and mounted in elevated position upon a suitable supporting structure 44 composed of insulating material. Loosely supported by the rings 42, 43 is a connector bar 45having' its end portions bent at right angles to its medial region to prevent it from being displaced from the rings, and for another purpose presently to be explained. Rings 42, 43 are electrically connected by conductors 4B and 4"! respectively with conductors l5 and I3 respectively of the main circuit. The arrangement is such that the rings 42, 48 and the bar 45 constitute a switch in the shunt circuit, which switch is closed when the bar 45 is at rest, whereby the resistance [4 is shunted out of the main circuit and the lamps [2 enabled to burn brightly. If the connector bar 45 is vibrated or oscillated, it will momentarily and intermittently break contact with one or both of the rings 42, 43, thereby opening the shunt circuit and enabling the resistance I4 to efiect the dimming of the lamps 12.

For vibrating and oscillating the bar 45, pneumatically operated mechanical means is provided, said mechanical means comprising a lamp shade 49 that is pivotally mounted upon an axial support 50. The latter is shown as an angular structure, the switch-supporting structure 44 also being mounted thereon. The lamp shade 49 is of the type having an annular series of openings 5| in the top thereof concentric with the axis of the shade, and vanes 52 attached to the top and eXtending obliquely over the respective openings. The lamp shade is positioned over a lamp 53 that is energized by electrical energy from the main circuit by means of conductors 54, 55 connected thereto. The arran ement is such that the heat of the lamp '53 creates convection currents of air that rise and pass through the openings 5| in the top of the lamp shade, the force of said currents against the vanes '52 being sufiicient to efiect rotation of the shade upon its axial support The top of the shade 49, on the under side thereof, is provided with an axially disposed bearing block 56 composed of dielectric material, the bottom of said block being formed with a conical recess or socket that receives the pointed upper end of the pivotal support 50, the arrangement being such as to create but slight frictional resistance to the rotation of the shade. Secured to the bearing block 56 and extending downwardly at opposite sides thereof are switch-operating rods 51, 51, the lower end portions of which are bent at right angles so as to be disposed radially of the axis of the shade.

The shunt switch is so mounted upon the support 50 that the downwardly extending portion of the switch bar 45, at one end thereof, extends into the orbit of the radially extending end portions of the operating rods 51, with the result that the bar 45 is oscillated and vibrated by the rods 51 as the lamp shade rotates upon its axis. This effects the intermittent dimming of the lamps [2 as previously explained.

Although the mechanical means for vibrating the shunt switch is shown as a lamp shade, and the pneumatic flow is thermally induced, the invention is not limited to this specific device, since the switch may be vibrated by pneumatic flow induced by other than thermal means, as will be apparent to those skilled in the art.

The device is simple in construction, is fully automatic in operation, and achieves the several advantages set out in the foregoing statement of objects.

Modification may be resorted to without departing from the spirit of the invention orthe scope thereof as defined by the appended claims.

What is claimed is:

1. A switch of the character described, comprising electrical conductor elements so lightly contacting each other that contact therebetween is broken by vibration of an element thereof, a lamp including a shade that is pivotally mounted and is rotated by convection currents set up by heat of the lamp, and an actuating member carried by said shade and moved in an orbit by rotation thereof, the said switch being positioned with one of its elements in the orbit of the actuating member of the shade and adapted to be vibrated by said member periodically as it moves in its orbit.

4 2. An electric switch of the character described comprising electrioal conductor elements so lightly contacting each other that contact therebetween is broken by vibration of an element thereof, a rotary structure having an actuating lement projecting therefrom and moving in an orbit, the switch having an element projecting into said orbit and vibrated periodically by impact of said actuating element therewith, and means for rotating the rotary structure by means of a current of air.

LEWIS P. CLARK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,506,832 Hellman Sept. 2, 1924 1,537,796 Bossard May 12, 1925 1,965,176 Eveland July 3, 1934 1,584,856 Hauck May 18, 1926 836,279 Schneider Nov. 20, 1906 2,164,349 Rypinski 1- July 3, 1939 1,579,237 ONeill Apr. 6, 1926 1,580,901 Jones Apr. 13, 1926 1,603,289 ONeill Oct. 19, 1926 1,817,468 Van Nostrand Aug. 4, 1931 1,441,902 Bailey Jan. 9, 1923 1,025,310 Robillot May 7, 1912 1,776,297 Sanderson Sept. 23, 1930 FOREIGN PATENTS Number Country Date 235,690 Great Britain June 25, 1925 

